1. Field of the Invention
The invention refers to a drift advancing or exploiting machine in particular equipped with a caterpillar chassis and comprising a cutting arm on which are arranged cutting heads and/or cutting rolls rotatably supported for being rotated around an axis transversely oriented relative to the advancing direction.
2. Description of the Prior Art
In usual cutting machines of the initially mentioned type, the cantiliever arm or cutting arm, respectively, is supported on a caterpillar chassis for being swivellable around a substantially vertical axis and around a substantially horizontal axis. For making excavations of greater cross section, the cantilever arm must be given a correspondingly great length, so that, when swivelling the cantilever arm in lateral direction or in height direction, there results an essentially arcuate mining face. In case of fragile mine roof, it is necessary to establish the provisional consolidation of the drift near the mine face for preventing collapsing of the mine roof. Such a provisional consolidation is relatively expensive and time-consuming and can, with consideration of the lateral swivellable cutting arm, not be advanced arbitrarily close to the mine face. Furthermore, such a provisional consolidation requires correspondingly expensive devices for transporting the consolidating frames and auxiliary equipment for erecting the consolidation above the cutting machine being operated in front of the mine face and the space at disposal within the area near the mine face is correspondingly restricted. Furthermore, with known devices it is only possible to erect the drift consolidation adjacent the drift face only when stopping the cutting work, because a reliable protecting means can not be arranged between the cutting tools and locations located adjacent the drift face, because this protecting means would collide with the universally swivellable cutting arm.